Acoustic tone equalizer



1966 R. P. MERCURIUS ACOUSTIC TONE EQUALIZER 2 Sheets-Sheet 1 FiledApril 26, 1965 INVENTOR.

zmpazfi I? 1 155601 2105 Feb. 8, 1966 R. P. MERCURIUS ACOUSTIC TONEEQUALIZER 2 SheetsSheet 2 Filed April 26, 1965 United States PatentOfiice 3,233,696 Patented Feb. 8, 1966 3,233,696 ACOUSTIC TONE EQUALIZERRandolph P. Mercurius, Bronx, N.Y., assignor to Rectilinear ResearchCorp, New York, NY. Filed Apr. 26, 1965, Ser. No. 450,683 4 Claims. (Cl.181-31) This invention relates to audio equipment and more particularlyto a sound system.

More specifically, this invention relates to sound systems of the typedisclosed in my prior patents, No. 2,277; 525 granted March 24, 1942,and No. 2,891,629 granted June 23, 1959, and has for its primary objectthe provision of an improved acoustic tone equalizer which canadequately and efficiently accommodate a capacity volume of soundemanating from both a set of dual general function speakers, and amid-range frequency speaker.

Still another object of this invention is to provide a sound systemwhich includes a single housing for enclosing the set of dual generalfunction speakers and the mid-range frequency speaker and bafiie devicesin a compact and efiicient arrangement. Another object of this inventionrelates to providing an auxiliary cabinet containing two sets of lowfrequency range dual speakers to be optionally used with the improvedacoustic tone equalizer in the single housing which can furtheradequately and efficiently handle the capacity volume added to thatemanating from the set of dual general function speakers and themid-range frequency speaker.

An additional object of this invention is to compartmentize the housingso as to contain the several speakers each in a separate compartmentprovided with a port therefor and to provide novel baffie means in thehousing that communicates both with the low frequency and mid frequencyranges speaker compartments so as to simultaneously amplify soundemanating therefrom and for directing the equalized sound wavesoutwardly through the ports.

Further objects of the invention will appear as the descriptionproceeds.

To the accomplishment of the above and related objects, my invention maybe embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstruction illustrated and described within the scope of the appendedclaims.

FIGURE 1 is a front perspective view of the housing embodying theinvention;

FIGURE 2 is a rear perspective view of the housing;

FIGURE 3 is a front perspective view of a speaker cabinet unit;

FIGURE 4 is a vertical sectional view of the cabinet taken on line 4-4,FIGURE 3;

FIGURE 5 is a front perspective view of the housing and cabinet inassembled relation;

FIGURE 6 is an exploded perspective view partly in section showingdetails of the compartments, speaker positions and baffle construction.

Referring more particularly to the drawings, an enclosure or housing 10made in accordance with the present invention, is of rectangularformation and is defined by side walls 12, 14; a top wall 16; a bottomWall 18, and a rear wall 20, all suitably joined together to form abox-like structure and supported on legs 22.

The side wall 12 is formed with a circular cut out or port 24, adjacenttop 16 for mounting a general function speaker 25, the port 24 beingcovered with a grill cloth 26 in the manner known. Similarly theopposite side wall 14 is provided with a like similarly positioned portfines of walls 51, 53, 55, 56.

28 for mounting a general function speaker 29, the port 28 being coveredwith a grill cloth 30.

Extending between the side walls 12, 14, slightly below the ports 24,28, is a horizontal partition 32 dividing the housing 10 into an uppergeneral function speaker compartment 34 and a lower mid-rang speakercompartment 36.

Extending transversely across the partition 32 and adjacent one endthereof, are parallel rows of openings 38, 39. A divider wall 40inclined with relation to the top 16 and partition 32, has its upperedge 41' secured to the top 16, see FIGURE 6, and its lower edge 42disposed above and between the rows of openings 38, 39; the divider wall14 separates the compartment 32 into two sound chambers 41, 42.Preferably, the inside edge of the divider 40 and partition 32 aresecured to the rear wall 20.

Below the partition 32, the side wall 14 is provided with a port 44, seeFIGURE 2, for mounting a mid-range speaker 45, see FIGURE 6, the port 44being covered with a grill cloth 46. v

A mid-range frequency baffle 56 is disposed in the midrange speakercompartment 36 and consists of a lower wall 51 of less length than thehousing bottom wall 18 and located in vertical spaced relation theretoand parallel therewith; vertical walls 52, 53, with wall 52 beingslightly of greater height than wall 53; and an upper inclined wall 54extending from the upper horizontal edge of vertical wall 52 to thehousing side wall 12, and secured thereto directly below thecorresponding edge of the partition 32, see FIGURE 6. Of less lengththan the lower wall 51, is a horizontal wall 55 extending from the upperedge of vertical wall 53 and parallel to lower wall 51, and dependingfrom the free edge of horizontal intermediate wall 55 is a dependingvertical wall 56 having its lower free edge 57 spaced from the lowerwall 51. Preferably all the walls 5156 are of the same width with theirinside edges secured to the rear housing wall 20.

The bafiie Stl provides a circuitous passage P that starts aboveinclined wall 54 and extends between housing side wall 14 and verticalwall 52, between housing bottom Wall 18 and lower wall 51, betweenvertical wall 53 and housing side wall 12, between bafiie walls 54, 55and 52, 56 to terminate in a tone chamber 58 within the con- Providedinthe rear wall 26 are two parallel vertical rows of openings 61), 61that open directly into the tone chamber 58. The rows of openings 66,61, are located adjacent end wall 53 of tone chamber 58.

As seen in FIGURE 6, the front of the housing 10 is open to provideaccess into the interior thereof and is closed by a removable front.panel 64 held secured in place by the fastener elements 65. Disposed inthe front panel 64 is a horizontal row of openings 68 which in themounted position of the front panel open into the tone chamber 58.

For optional use with the speaker housing 10, a cabinet 76 is providedwhich consists of top and bottom walls '71, 72, and side walls 73, 74,joined together in rectangular form and provided with a front panel 75.Formed in the panel are four ports 76, each mounting a low frequencyspeaker 80. The speakers are each located in a separate compartmentprovided by the intersecting partitions 81, 82, the ends of whichterminate short of the opposed walls of the cabinet, see FIGURE 3, toprovide a passage therearound. Extending across the ports 76 is a grillcloth 85. The rear of the cabinet 76) is open and the cabinet 76 may bemounted on the front panel 64 of the housing 10 in any desired manner.When so mounted, see FIGURE 5, the horizontal openings 68 in the frontpanel will communicate with the interior of the speaker cabinet 70.

Itwill' be recognized that the sound waves emanating from the generalfunction speakers 25, 29, will pass directly into the mid range speakercompartment 36 through openings 38, 39, to mix with the sound wavesemanating from the mid range speaker 45. It is to be noted that theinitial portion P of the passage P into which the sound waves enter fromopenings 38, 39 increases in volume as it approaches the mid rangespeaker 45. This mixing of the sound waves equalize each other as theycontinue through the passage P into the tone chamber 58, from which theyare directed outwardly through the openings 6%, 61 in the rear wall andthe openings 68 in the front panel 64.:

When the cabinet 70 with the low frequency speakers is mounted on thehousing 10, the sound Waves emanating from the low frequency speakers30, will enter the initial portion P of the passage P through theopenings es to mix with the combined mix of the sound waves emanatingfrom the speakers 25, 29 and 45. I

Since the sound waves of all of the speakers, either in the housing 10alone, or in addition to that from the speakers 80 of cabinet 70 whenattached to housing lid, are directed through a single tone chamber,such the efifect of equalizing the tone of all of the speakers, wherebythe sound produced thereby is directed outwardly through the openings60, 61. Thus, a very eificient and compact acoustic tone equalizerenclosure has been provided which can be used for a Wide variety ofpurposes in any audio system.

While certain novel features of my invention have been shown anddescribed and are pointed out in the annexed claims, it will beunderstood that various omissions, substitutions and changes in theforms and de tails of the device illustrated and in its operation can bemade by those skilled in the art without departing from the spirit ofthe invention.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. An acoustic tone equalizer comprising:

(a) a rectangular housing having top and bottom walls,

side walls and a rear wall,

(b) a removable closure panel forming the front wall of said housing,

(c) a horizontal partition extending between said side Walls definingwithin said housing upper and lower compartments of unequal size withthe upper coinpartment smaller than the lower compartment,

(d) a first port in each housing side wall between said partition andsaid housing top wall,

(e) a general function speaker mounted at each first port,

(f) a divider extending downwardly at an inclination from the housingtopwall, with its lower free end spaced from said partition, and locatedsubstantially mid-way between the transverse center of said partitionand an adjacent housing side wall,

(g) a double transverse row of openings in said par- 4- tition below thefree end of said divider with each row lying one on each side of atransverse vertical plane passing through said divider free end.

(h) a second port in the housing side wall furthest remote from saidtransverse partition openings, (i) a mid range speaker mounted at saidsecond port, (j) a bafi'le structure in said lower compartment providinga circuitous passage having an initial inlet portion of increasingvolume and a terminal outlet portion defining a tone chamber, and

(k) at least one outlet opening in said rear housing wall positionedwithin the confines of said tone chamber.

2, The acoustic tone equalizer of claim 1, including:

(a) at least one outlet opening in said front closure panel positionedwithin the confines of said tone chamber, and wherein (b) said rows ofpartition openings are located to communicate with the smaller end ofsaid passage initial inlet portion, and

(c) said mid range speaker lying opposite to the larger end of saidpassage initial inlet portion.

3. The acoustic tone equalizer of claim 2, wherein:

(a) said circuitous passage is defined by planar wall sections of saidbafile structure disposed parallel to the housing side walls and thehousing bottom wall, and

(b) said initial inlet portion of said passage is defined by a planarwall section inclined with relation to said portion wtih one end thereofconnected to the housing side wall opposite the mid range speaker andadjacent housing to the end of the partition secured to said housingside wall, and

(c) the other and lower end of said inclined wall section connected tothe wall section parallel to the opposite housing side wall.

4. The acoustic tone equalizer of claim 3, wherein (a) said tone chamberis defined by wall sections of said bafiie structure,

(b) the penultimate wall section lying below said in clined wall sectionand parallel to said housing bottom wall, and

(c) the terminal wall section lying parallel to the wall sectionopposite the housing side wall mounting the mid range speaker with itsfree end spaced from the wall section parallel to the housing bottomwall lying below said penultimate wall section,

References Qited by the Examiner UNITED STATES PATENTS 2,891,629 6/1959Mercurius 181-31 FOREIGN PATENTS 579,129 7/ 1959 Canada.

LEO SMILOW, Primary Examiner.

1. AN ACOUSTIC TONE EQUALIZER COMPRISING: (A) A RECTANGULAR HOUSINGHAVING TOP AND BOTTOM WALLS, SIDE WALLS AND A REAR WALL, (B) A REMOVABLECLOSURE PANEL FORMING THE FRONT WALL OF SAID HOUSING, (C) A HORIZONTALPARTITION EXTENDING BETWEEN SAID SIDE WALLS DEFINING WITHIN SAID HOUSINGUPPER AND LOWER COMPARTMENTS OF UNEQUAL SIZE WITH THE UPPER COMPARTMENTSMALLER THAN THE LOWER COMPARTMENT, (D) A FIRST PORT IN EACH HOUSINGSIDE WALL BETWEEN SAID PARTITION AND SAID HOUSING TOP WALL, (E) AGENERAL FUNCTION SPEAKER MOUNTED AT EACH FIRST PORT, (F) A DIVIDEREXENDING DOWNWARDLY AT AN INCLINATION FROM THE HOUSING TOP WALL, WITHITS LOWER FREE END SPACED FROM SAID PARTITION, AND LOCATED SUBSTANTIALLYMID-WAY BETWEEN THE TRANSVERSE CENTER OF SAID PARTITION AND AN ADJACENTHOUSING SIDE WALL, (G) A DOUBLE TRANSVERSE ROW OF OPENINGS IN SAIDPARTITION BELOW THE FREE END OF SAID DIVIDER WITH EACH ROW LYING ONE ONEACH SIDE OF A TRANSVERSE VERTICAL PLANE PASSING THROUGH SAID DIVIDERFREE END.